title: Martentoxin, a large-conductance Ca(2+)-activated K(+) channel inhibitor, attenuated TNF-α-induced nitric oxide release by human umbilical vein endothelial cells.
abstract: Martentoxin, a 4,046 Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch, has been demonstrated to block large-conductance Ca(2+)-activated K(+) (BKCa) channels; however, its biological roles are still largely unknown. In the present study, we investigated the pharmacological effects of martentoxin on regulating the production of nitric oxide induced by TNF-α in human umbilical vein endothelial cells (HUVECs). We found that, 1, 10 and 100 µmol/L martentoxin decreased nitric oxide production by HUVECs exposed to 10 ng/mL TNF for 6, 12 and 24 hours. We further demonstrated that martentoxin inhibited the activity of iNOS and retarded the down-regulation of eNOS mRNA induced by TNF-α. Therefore, martentoxin could be a potential therapeutic agent for vascular diseases.
authors.affiliation: Department of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Wenyi
authors.initials: W
authors.lastname: Qian
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhu
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Huan
authors.forename: Rong
authors.initials: R
authors.lastname: Gao
authors.forename: Hang
authors.initials: H
authors.lastname: Xiao
keywords: Buthus martensiiKarsch; human umbilical vein endothelial cells (HUVECs); martentoxin; nitric oxide